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    <title>Document</title>
    <script>
        // 代表 空，否定的值 会被转换为 false
        console.log(Boolean('')); // false
        console.log(Boolean(0));  // false
        console.log(Boolean(NaN));  // false
        console.log(Boolean(null));  // false
        console.log(Boolean(undefined));  // false
        console.log('---------------------------');
        console.log(Boolean('123'));  // true
        console.log(Boolean('你好吗'));  // true
        console.log(Boolean('我很好'));  // true
    </script>
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